Boat trim tab and method of manufacturing same

ABSTRACT

A trim tab for a power boat comprises a first portion adapted to attach to a transom of the power boat, a second portion adapted to contact, at a variable angle, a fluid in which the power boat is being operated to control a trim angle of the power boat, and a live hinge adapted to hingedly affix the second portion to the first portion. The first and second portions may be constructed of aluminum. The live hinge may comprise a strip of a thermoplastic polymeric material having a relatively thin center section spanning a gap between the first and second portions and having relatively thick edge sections on opposite sides of the center section. The thermoplastic polymeric material may comprise polypropylene. The first and second portions may each define a gap for receiving one edge section of the live hinge.

FIELD OF THE INVENTION

The present invention relates in general to control surfaces of watercraft such as a power boat, and more specifically to a trim tab for such watercraft.

BACKGROUND OF THE INVENTION

The present invention relates to a trim tab for a power boat, and to a method of manufacturing a trim tab. Trim tabs 14 are typically attached to the transom 12 of a boat 10, as illustrated in FIG. 1, and are used to adjust the trim (i.e., the fore-and-aft angle and the thwartship angle of the boat relative to the water) while the boat is being propelled. As a power boat accelerates, the bow rises thereby increasing the angle of the boat relative to the water. To improve operating performance of the boat, it is desirable to counteract this bow rise and force the boat into a more level attitude. Because the trim tab is submerged (partially or fully) in the water and is at an angle relative to the surface of the water, water flowing under the trim tab causes an upward force on the trim tab. This lifting force causes the stern to rise, thereby lowering the trim angle. The greater the angle of the trim tab relative to the water, the greater the upward force on the trim tab. As illustrated in FIG. 1, actuators 16 are attached to the transom and to each trim tab. The actuators are typically electromechanically or hydraulically controlled and extend/contract to change the angle of the trim tab relative to the plane of the bottom of the hull. Adjusting the boat's trim angle in this manner increases speed, reduces fuel consumption, improves visibility and may produce a smoother ride.

FIG. 1 illustrates the use of two trim tabs 14 on a boat, however more than two trim tabs might be used for a large boat and only one trim tab might be used for fore-and-aft trim only. Based partly on the number of trim tabs used and the size of the boat, the width (i.e., the thwartship dimension) of the required trim tab(s) may vary greatly. As a result, numerous stock keeping units (SKUs) are needed to satisfy all customers, thereby requiring a large and expensive inventory and increasing the likelihood of being out of stock of a particular size desired by a customer.

Referring now to FIGS. 2 and 3, a perspective view and a top view, respectively, of a known trim tab are illustrated. The trim tab of FIGS. 2 and 3 is typically constructed of stainless steel to resist corrosion. Corrosion resistance is important due to the harsh saltwater environment to which the trim tab may be subjected. The prior art trim tab of FIGS. 2 and 3 comprises a portion 14 adapted to attach to a transom of the boat and a portion 18 adapted to contact the water. In this trim tab, the two portions each have multiple loops 20 that are interlaced to form a standard hinge. A hinge pin 22 is positioned within the interlaced loops to secure the two portions together while allowing angular movement of the portion which contacts the water. Each portion is formed initially with rectangular tabs, and these rectangular tabs are bent to form the loops. This type of hinge results in gaps between the hinge loops that cause water to spray upward as the boat is propelled forward. This upward spray of water is undesirable as it may force water to accumulate in areas of the boat or on parts of the boat where accumulated water may cause damage.

Another drawback of the trim tabs of FIGS. 2 and 3 is that water can accumulate in the hinge loops, resulting in corrosion of the hinge pin and of the hinge itself.

There is a need for an improved trim tab for power boats which is economical to manufacture in numerous widths and small incremental sizes and which is highly resistant to corrosion.

BRIEF SUMMARY OF THE INVENTION

Generally described, exemplary embodiments of the invention provide an improvement of the known prior art by providing a boat trim tab having a live hinge connecting two portions, and a method of manufacturing the same.

In one exemplary embodiment, a trim tab for a power boat comprises a first portion adapted to attach to a transom of the power boat, a second portion adapted to contact, at a variable angle, a fluid in which the power boat is being operated to control a trim angle of the power boat, and a live hinge adapted to hingedly affix the second portion to the first portion. The first portion, the second portion, and the live hinge may be constructed of an extrudable material, such as aluminum or a polymer. For example, the first aid second portions may be constructed of aluminum, while the live hinge may comprise a strip of a thermoplastic polymeric material having a relatively thin center section spanning a gap between the first and second portions and having relatively thick edge sections on opposite sides of the center section. The thermoplastic polymeric material may comprise polypropylene. The first and second portions may each define a gap for receiving one edge section of the live hinge. Alternatively, the first portion, the second portion, and the live hinge may be constructed as a single unitary piece.

In another exemplary embodiment, a method of manufacturing a trim tab for a power boat comprises the steps of: (1) providing trim tab stock material comprising (a) stock material for a first portion adapted to attach to a transom of the power boat, (b) stock material for a second portion adapted to contact, at a variable angle, a fluid in which the power boat is being operated to control a trim angle of the power boat and (c) stock material for a live hinge adapted to hingedly affix the second portion to the first portion; (2) cutting the stock material to a customer-specified width; and (3) assembling the cut stock material into a trim tab having the customer-specified width.

The second portion stock material may be selected from stock material having one of a plurality of pre-determined lengths. The first and second portion stock material may be constructed of aluminum. The live hinge stock material may comprise a strip of a thermoplastic polymeric material having a relatively thin center section and having relatively thick edge sections on opposite sides of the center section. The thermoplastic polymeric material may comprise polypropylene. The first and second portion stock materials may each define a gap for receiving one edge section of the live hinge stock material.

In another exemplary embodiment, a trim tab for a power boat comprises a first portion and a second portion. The first portion comprises a transom attachment portion and a live hinge portion. The second portion is adapted to contact, at a variable angle, a fluid in which the power boat is being operated to control a trim angle of the power boat. The transom attachment portion is adapted to attach to a transom of the power boat and the live hinge portion is adapted to hingedly affix the second portion to the transom attachment portion of the first portion.

The live hinge portion may comprise a relatively thick distal portion adapted to be affixed to the second portion and a relatively thin flexible portion spanning the edge portion and the transom attachment portion. The second portion may define a gap for receiving the distal portion. The transom attachment portion may define a channel adapted to receive a washer plate. The first portion may be constructed of a thermoplastic polymeric material and the second portion is constructed of aluminum.

In another exemplary embodiment, a method of manufacturing a trim tab for a power boat comprises the steps of: (1) providing trim tab stock material comprising (a) stock material for a first portion adapted to attach to a transom of the power boat and comprising a transom attachment portion and a live hinge portion and (b) stock material for a second portion adapted to contact, at a variable angle, a fluid in which the power boat is being operated to control a trim angle of the power boat; (2) cutting the stock material to a customer-specified width; and (3) assembling the cut stock material into a trim tab having the customer-specified width.

The second portion stock material may be selected from stock material having one of a plurality of pre-determined lengths. The live hinge portion may comprise a relatively thick distal portion adapted to be affixed to the second portion and a relatively thin flexible portion spanning the edge portion and the transom attachment portion. The second portion may define a gap for receiving the distal portion. The transom attachment portion may define a channel adapted to receive a washer plate. The first portion may be constructed of a thermoplastic polymeric material and the second portion is constructed of aluminum.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

Having thus described the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:

FIG. 1 illustrates a perspective view of power boat with two trim tabs mounted on the transom;

FIG. 2 illustrates a perspective view of a prior art trim tab;

FIG. 3 illustrates a side view of the prior art trim tab of FIG. 2;

FIG. 4 illustrates a perspective view of a trim tab, in accordance with an embodiment of the invention;

FIG. 5 illustrates a side view of the trim tab of FIG. 4;

FIG. 6 illustrates a side view of the live hinge portion of the trim tab of FIG. 4;

FIG. 7 illustrates a perspective view of a trim tab, in accordance with an alternative embodiment of the invention;

FIG. 8 illustrates a side view of the trim tab of FIG. 7;

FIG. 6 illustrates a side view of the first portion of the trim tab of FIG. 7; and

FIG. 10 illustrates a perspective view of a washer plate of the trim tab of FIG. 7.

DETAILED DESCRIPTION OF THE INVENTION

The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout.

Referring now to FIGS. 4 and 5, perspective and top views of a trim tab are illustrated, in accordance with an embodiment of the invention. The trim tab of FIGS. 4 and 5 comprises a first portion 42, a second portion 44, and live hinge 46. The first portion, the second portion, and the live hinge may be constructed of an extrudable material, such as aluminum or a polymer, as discussed in greater detail below. The first portion is adapted to attach to a transom of a power boat, using any suitable attachment means, such as bolts/nuts or screws. The second portion is adapted to contact, at a variable angle, the water in which the power boat is being operated to control a trim angle of the power boat. The live hinge is adapted to hingedly affix the second portion to the first portion.

A live hinge (also termed a living hinge) is a one-piece, pinless hinge. Referring now to FIG. 6, a side view of the live hinge portion of the trim tab of FIGS. 4 and 5 is illustrated, in accordance with an embodiment of the invention. The live hinge 46 of the trim tab of FIGS. 4 and 5 comprises a strip of a thermoplastic polymeric material having a relatively thin center section 48 that spans a gap between the first and second portions aid having relatively thick edge sections 50 on opposite sides of the center section. Alternatively, the live hinge material may have a uniform thickness. The thermoplastic polymeric material may comprise polypropylene, due to its high fatigue resistance. The live hinge material may alternatively be constructed of other polymers or copolymers. The thin center section bends to allow angular movement of the second portion relative to the fixed first portion. The lack of friction or weal in such a hinge makes the live hinge very durable. As can be seen in FIGS. 4 and 5, the first and second portions 42 and 44 each define a gap 43 and 45 respectively for securely receiving one edge section 50 of the live hinge. The two edge sections 50 may be inserted into the gaps 43 and 45 in first and second portions, and the area defining the gaps may be crimped or otherwise compressed toward the live hinge to help securely retain the edge sections within the gaps. Alternatively, a rivet, screw, or nut and bolt may be fixed into or through the first and/or second portions 42 and 44 and through or into the edge section(s) 50 to secure the live hinge within the gaps.

The live hinge trim tab of FIGS. 4 and 5 has many advantages over the trim tab of FIGS. 2 and 3 with the loop-and-pin type hinge. Water cannot easily accumulate in any portion of the live hinge trim tab, thereby eliminating a potential source of corrosion. The continuous nature of the live hinge prevents water from coming through the hinge and spraying upward. Because there is no metal-to-metal contact in the live hinge trim tab, a corrosion-resistant coating may be applied to all of the metal components (i.e., the first and second portions), such as by anodizing, powder coating, or painting, to provide additional protection and durability. The metal-to-metal contact of the loop-and-pin type hinge would likely wear away any such coating. Cosmetically, the coating on the tab may be colored or multi-colored in accordance with the preference of a customer.

Further, the live hinge trim tab of FIGS. 4 and 5 can be manufactured very easily. The first and second portions may be cast, machined, or extruded, with extrusion being a preferred method. The first and second portions and the live hinge may then be assembled. The prior art trim tab of FIGS. 2 and 3 requires the first and second portions to be cast or machined, then the hinge loops formed by bending (as discussed above) before the components may be assembled. This extra step of forming the hinge loops is time consuming and requires specialized equipment.

The first and second portions of the trim tab of FIGS. 4 and 5 may be extruded in aluminum, rather than the stainless steel used to construct the prior art trim tab. Aluminum can provide excellent corrosion resistance, and is lighterweight and much less costly than stainless steel. Further, aluminum can be anodized to provide additional corrosion resistance. The prior art trim tab of FIGS. 2 and 3 cannot readily be constructed of aluminum, as the loop-and-pin hinges are created by bending parts of the first and second portions and hard, corrosion-resistant aluminum cannot be bent in that manner. To construct an aluminum trim tab similar to that of FIGS. 2 and 3, each portion may be formed initially with smaller rectangular tabs and pre-formed tubes may be welded to these rectangular tabs to form the hinge loops. While it is possible to weld hinge loops to an aluminum trim tab as described, aluminum welding requires specialized expertise. Further, such an aluminum trim tab with welded hinge loops would have the same drawbacks (described above) as the stainless steel trim tab of FIGS. 2 and 3.

As discussed above, a supplier of known trim tabs would typically have to maintain an inventory of a large number of SKUs. However, the trim tab of the present invention may be manufactured in such a way as to significantly reduce the number of SKUs that a supplier would need to have in inventory. In such a method of manufacturing a trim tab, the supplier may maintain an inventory of trim tab stock material. This stock material would typically be stocked in relatively long widths (e.g., twelve feet), cut to the customer's desired width, and assembled. The trim tab stock material would typically comprise: (1) stock material for the portion adapted to attach to the transom; (2) stock material for the portion adapted to contact the water at a variable angle; and (3) stock material for the live hinge. The stock material of the portion adapted to contact the water at a variable angle would typically be stocked in two pre-determined lengths (e.g., nine and twelve inches). From just these four SKUs, an almost infinite number of trim tab sizes may be provided to meet almost any customer's needs.

The stock material for the portion adapted to attach to the transom and the portion adapted to contact the water is constructed of aluminum. The live hinge stock material comprises a strip of a thermoplastic polymeric material, typically polypropylene, having a relatively thin center section and having relatively thick edge sections on opposite sides of the center section. Cutting the stock material to the desired width is relatively easy, as aluminum and polypropylene may be cut with tools that are available in many light-industrial facilities. The cut stock may then be easily assembled into a trim tab by sliding the live hinge portion into the gaps defined in the other two portions.

The number of trim tabs that may be cut from a piece of stock material will vary depending upon the desired width and the overall width of the stock material. After cutting the portions of several trim tabs from a stock portion, any leftover material that is insufficient for another trim tab may be readily recycled. However, the stock material usage may be optimized by carefully planning the widths to be cut from a particular piece of stock material. For example, a piece of stock material may be twelve feet (i.e., 144 inches). From such a piece of stock material, the following trim tabs may be cut according to customer requirements: (1) a trim tab 42 inches wide (leaving 102 inches of stock material); (2) a trim tab 30 inches wide (leaving 72 inches of stock material); (3) a trim tab 36 inches wide (leaving 36 inches of stock material); and a trim tab 18 inches wide (leaving 18 inches of stock material). It may then be desirable to reserve this remaining 18 inch piece of stock material for use as either a single 18 inch trim tab or as two 9 inch trim tabs, thus producing no scrap material from this piece of stock material.

The examples noted herein are directed to aluminum. In one example, the aluminum is ¼ inch thick. Aluminum is lightweight relative to stainless steel, and is very strong. Other metals or rigid materials which can be molded of extruded may be used with respect to the first and second portions. Further, because the live hinge provides a physical separation of the first and second portions, the materials that make up the first and second portions may be different. For example, the first portion may be acrylic or fiberglass and the second portion metal.

Referring now to FIGS. 7 and 8, perspective and side views of a trim tab are respectively illustrated, in accordance with an alternative embodiment of the invention. The trim tab 60 of FIGS. 7 and 8 comprises a first portion 62 and a second portion 44. In contrast to the trim tab 40 of FIGS. 4 and 5 which comprises at least three separate portions (i.e., a first portion attached to the transom, a second portion in contact with the water, and a live hinge hingedly affixing the first and second portions), the trim tab of FIGS. 7 and 8 comprises as few as two separate portions. This is possible because the first portion functions both to attach the trim tab to the boat transom and as a live hinge to which the second portion is affixed. As in the trim tab 40 of FIGS. 4 and 5, the second portion 44 of the trim tab 60 of FIGS. 7 and 8 is adapted to contact, at a variable angle, a fluid in which the power boat is being operated to control a trim angle of the power boat. In the trim tab of FIGS. 7 and 8, the first portion may be constructed of a thermoplastic polymeric material, typically polypropylene, and is typically constructed via an extrusion process. The second portion may be constructed of aluminum, and is also typically constructed via an extrusion process.

Referring now to FIG. 9, a side view of the first portion 62 of the trim tab of FIG. 7 is illustrated. The first portion comprises a transom attachment portion 74 and a live hinge portion 71. The live hinge portion 71 is adapted to hingedly affix the second portion 44 to the transom attachment portion 74 of the first portion 62. The live hinge portion may comprise a relatively thick (as compared to the flexible portion 72) distal portion 70 which is adapted to be affixed to the second portion. As can be seen in FIG. 8, the second portion 62 may define a gap for receiving the distal portion of the live hinge portion. The live hinge portion 71 may further comprise a relatively thin flexible portion 72 spanning the distal portion and the transom attachment portion and enabling the necessary movement of the second portion.

The transom attachment portion 74 of the first portion 62 is adapted to attach to a transom of the power boat, using any suitable attachment means, such as bolts/nuts or screws. The transom attachment portion may define a charmer 66 adapted to receive a washer plate 64. FIG. 10 illustrates a perspective view of such a washer plate. As can be seen in FIG. 10, a washer plate typically has a rectangular parallelepiped shape and has several through-holes 76 to receive the attachment bolts or screws. Washer plates can prevent the bolt heads or screw heads from “biting” into the transom attachment portion and can more evenly distribute the mechanical stress to provide a more secure attachment of the trim tab to the transom. The washer plate is constructed of stainless steel, aluminum, or some other corrosion-resistant material. The transom attachment portion may have lips 68 along the edges of the channel 66 to help retain the washer plate within the channel. Once the washer plate is positioned within the channel, the trim tab may be positioned at the mounting location on the transom for installation. The washer plate holes provide a guide for where the installer should drill pilot holes through the transom attachment portion and through the transom.

As discussed above regarding the trim tab of FIGS. 4 and 5, the trim tab of FIGS. 7 and 8 may be manufactured in such a way as to significantly reduce the number of SKUs that a supplier would need to have in inventory. In such a method of manufacturing a trim tab, the supplier may maintain an inventory of trim tab stock material. This stock material would typically be stocked in relatively long widths (e.g., twelve feet), cut to the customer's desired width, and assembled. The trim tab stock material would typically comprise: (1) stock material for the first portion (i.e., the portion comprising the transom attachment portion and the live hinge portion); and (2) stock material for the second portion (i.e., the portion adapted to contact the water at a variable angle). The stock material of the portion adapted to contact the water at a variable angle would typically be stocked in two pre-determined lengths (e.g., nine and twelve inches). From just these three SKUs, an almost infinite number of trim tab sizes may be provided to meet almost any customer's needs. Additionally, washer plate stock material would be stocked.

The stock material for the portion adapted to attach to contact the water is constructed of aluminum. The stock material for the first portion is constructed of a thermoplastic polymeric material, typically polypropylene, having the profile illustrated in FIG. 9. Cutting the stock material to the desired width is relatively easy, as aluminum and polypropylene may be cut with tools that are available in many light-industrial facilities. The cut stock may then be easily assembled into a trim tab by sliding the distal portion 70 of the first portion into the gaps defined in the second portion. The washer plate stock material may then also be cut to the same desired width and slid into the channel 66.

Although not illustrated, an additional alternative embodiment of the invention exists in which the entire trim tab (i.e., the first portion, the second portion, and the live hinge) may be constructed as a single unitary piece. Such a entire trim tab may be constructed of a polymer. In such an embodiment, the first and second portions would typically be relatively thick to provide sufficient strength and rigidity, while the live hinge would be relatively thin to provide sufficient flexibility. The unitary trim tab may be constructed via an extrusion process. A stretching process may be applied to the live hinge to thin the live hinge, while also increasing flexibility and strength of the live hinge.

Many modifications and other embodiments of the invention will come to mind to one skilled in the art to which this invention pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation. 

1. A trim tab for a power boat, comprising: a first portion adapted to attach to a transom of the power boat; a second portion adapted to contact, at a variable angle, a fluid in which the power boat is being operated to control a trim angle of the power boat; and a live hinge adapted to hingedly affix the second portion to the first portion; wherein the live hinge comprises a strip of a thermoplastic polymeric material having a relatively thin center section spanning a gap between the first and second portions and having relatively thick edge sections on opposite sides of the center section, and wherein the first and second portions each define a gap for receiving one edge section of the live hinge, each gap spanning an entire width of the respective first and second portion.
 2. The trim tab of claim 1, wherein the first portion, the second portion, and the live hinge are constructed of an extrudable material.
 3. The trim tab of claim 1, wherein the first and second portions are constructed of aluminum.
 4. (canceled)
 5. The trim tab of claim 1, wherein the thermoplastic polymeric material comprises polypropylene.
 6. (canceled)
 7. (canceled)
 8. A method of manufacturing a trim tab for a power boat, the method comprising: providing trim tab stock material comprising (a) stock material for a first portion adapted to attach to a transom of the power boat, (b) stock material for a second portion adapted to contact, at a variable angle, a fluid in which the power boat is being operated to control a trim angle of the power boat and (c) stock material for a live hinge adapted to hingedly affix the second portion to the first portion; cutting the stock material to a customer-specified width; and assembling the cut stock material into a trim tab having the customer-specified width.
 9. The method of claim 8, wherein the second portion stock material is selected from stock material having one of a plurality of pre-determined lengths.
 10. The method of claim 8, wherein the first and second portion stock material is constructed of aluminum.
 11. The method of claim 8, wherein the live hinge stock material comprises a strip of a thermoplastic polymeric material having a relatively thin center section and having relatively thick edge sections on opposite sides of the center section.
 12. The method of claim 11, wherein the thermoplastic polymeric material comprises polypropylene.
 13. The method of claim 11, wherein the first and second portion stock materials each define a gap for receiving one edge section of the live hinge stock material.
 14. A trim tab for a power boat, comprising: a first portion comprising a transom attachment portion and a live hinge portion; and a second portion adapted to contact, at a variable angle, a fluid in which the power boat is being operated to control a trim angle of the power boat; wherein the transom attachment portion is adapted to attach to a transom of the power boat, wherein the live hinge portion is adapted to hingedly affix the second portion to the transom attachment portion of the first portion, wherein the second portion defines a gap spanning an entire width of the second portion for receiving the distal portion.
 15. The trim tab of claim 14, wherein the live hinge portion comprises a relatively thick distal portion adapted to be affixed to the second portion and a relatively thin flexible portion spanning the edge portion and the transom attachment portion.
 16. (canceled)
 17. The trim tab of claim 14, wherein the transom attachment portion defines a channel adapted to receive a washer plate.
 18. The trim tab of claim 14, wherein the first portion is constructed of a thermoplastic polymeric material and the second portion is constructed of aluminum.
 19. A method of manufacturing a trim tab for a power boat, the method comprising: providing trim tab stock material comprising (a) stock material for a first portion adapted to attach to a transom of the power boat and comprising a transom attachment portion and a live hinge portion and (b) stock material for a second portion adapted to contact, at a variable angle, a fluid in which the power boat is being operated to control a trim angle of the power boat; cutting the stock material to a customer-specified width; and assembling the cut stock material into a trim tab having the customer-specified width.
 20. The method of claim 19, wherein the second portion stock material is selected from stock material having one of a plurality of pre-determined lengths.
 21. The method of claim 19, wherein the live hinge portion comprises a relatively thick distal portion adapted to be affixed to the second portion and a relatively thin flexible portion spanning the edge portion and the transom attachment portion.
 22. The method of claim 21, wherein the second portion defines a gap for receiving the distal portion.
 23. The method of claim 19, wherein the transom attachment portion defines a channel adapted to receive a washer plate.
 24. The method of claim 19, wherein the first portion is constructed of a thermoplastic polymeric material and the second portion is constructed of aluminum. 